Design and analysis of a switched‐capacitor DC‐DC converter with variable conversion ratio

Nazari

et al. 2021

IET Power Electronics

In many modern applications such as renewable energy sources (RESs), DC-DC step-up converters can be used to regulate the input variable and/or low voltage to achieve the desired characteristics such as amplitude and ripples at the output voltage. This article proposes a new transformer-less step-up DC-DC converter which, compared to previously presented converter topologies in the same class, can provide a higher variable voltage conversion ratio besides benefits such as decreased voltage stress on the switched-capacitors and power switches. Since the proposed topology is expandable, it can generate much higher voltage conversion ratios with lower, non-extreme duty-cycles which can be provided by a simple and cheap control circuit. The aforementioned advantages make the converter a suitable candidate for numerous industrial applications such as RES applications. Besides the voltage regulation applications, the proposed converter can be employed to extract the maximum power from RESs such as photovoltaic panels. To prove the converter performance, comprehensive comparisons and experiments are performed.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Section: Comparisonsmentioning

confidence: 99%

A new transformer‐less step‐up DC–DC converter with high voltage gain and reduced voltage stress on switched‐capacitors and power switches for renewable energy source applications

Nazari

et al. 2021

IET Power Electronics

“…To achieve higher efficiency, adjacent inductor topologies using active or passive clamp structures are used. This technique gives a soft‐switching condition to the power switch 31–42 …”

Section: Introductionmentioning

confidence: 99%

A design for switched capacitor and single‐switch DC–DC boost converter by a small signal‐based PI controller

Ertekin

Bulut

Tekin

et al. 2022

Circuit Theory & Apps

In this study, a switched capacitor (SC)‐based single‐switch DC–DC boost converter structure operating under the high voltage gain and the low duty ratio is proposed using the PI control technique. High current and voltage stresses across the power switches and power diodes can be reduced by using the projected SC block. In addition, the proposed converter can achieve high voltage gain through shorter duty cycles, which directly reduces the voltage stress and dynamic losses in the power semiconductors. On the other hand, because the proposed converter includes a single power switch under different output powers and different loads, the control process is simpler than multiswitch structures. With the proposed converter, an output voltage of 10 times greater rather than the input voltage is obtained at 0.57 of the duty cycle. In this study, the fundamental functions of the proposed converter and the controller design steps are analyzed mathematically and tested in MATLAB/SIMULINK environment. As a result of the analysis, it was determined that the proposed topology works with a high performance at high frequency and variable load ranges. To validate the proposed converter and theoretical calculations, a 200‐W prototype was established under a continuous conduction mode (CCM) working state, with 48‐VDC input voltage and 400‐VDC output voltage. Finally, the simulation results were tested and verified through the experimental results.

“…However, power losses, input current ripple, and the voltage stress across the semiconductors become large due to the extreme duty cycle of the switches. 7 Various topologies have been introduced to solve these problems for both isolated [8][9][10][11] and non-isolated [12][13][14][15] converters. The isolated converters have many uses due to their high reliability and simple structure.…”

Section: Introductionmentioning

confidence: 99%

A novel soft‐switched interleaved high step‐up DC–DC converter for high‐efficiency conversion

Sadighi

Afjei

Salemnia

2021

Circuit Theory & Apps

The present study aims to present a new interleaved soft-switched high stepup DC-DC converter, which is suitable for renewable energy sources, by integrating built-in transformer. A high conversion ratio is achieved by adjusting the turns ratio of the built-in transformer and duty cycle. The proposed converter uses active clamped circuit, which provides zero-voltage switching (ZVS) and a zero-current switching (ZCS) operation for all switches and diodes, respectively. Therefore, the losses caused by reverse recovery are considerably alleviated by providing ZCS condition in the diodes. The proposed structure has some advantages such as low-voltage stress across power switches, very low-input current ripple, fewer components, and lower cost.The MOSFET with low drain-source resistance can be used due to the lowvoltage stress, which could reduce conduction losses. Furthermore, a 500-W, 48-V input to 380-V output laboratory prototype is built and tested to validate the performance of the proposed topology.